SIR - There is growing concern about the mental health of teenagers in the UK. Schools are reporting increasing levels of stress and “low spirits”, both of which might manifest themselves in student self-harm. PE teachers are wary of youngsters who insist on keeping their arms forever covered because all to often an arm revealed show up self-inflicted cuts.

Teachers, and governors, are quite right to seek to act in these circumstances and work towards prevention. I was a teacher for 30 years and remain a secondary school governor, so I have some knowledge of this topic.

By the same token I have some knowledge of economics (my teaching subject) and considerable experience of politics . I therefore make it my task persistently write to newspapers advising against the dangers of Brexit.

If Brexit goes ahead it will be a huge act of self-harm.

This is not just my opinion but the view of every dispassionate organisation – be it the government's own OBR or an independent institute (IFS) or numerous academic economists in our best universities. Harm is already taking place (the slowdown of foreign investment into the UK and the acceleration of investment out).

John Cole, Oakroyd Terrace, Baildon